[D] Bothriospondylus madagascariensis
Describer
Lydekker, 1895
Time
Jurassic Middle Bathonian
Classification
Saurischia Sauropodomorpha Sauropoda Brachiosauridae
Diet
Herbivore
Fossilsite
Isalo Formation, Majunga, Madagascar
Fall Under
Bothriospondylus
Info
Bothriospondylus (Owen, 1875) = ?Marmarospondylus (Owen, 1875) Bothriospondylus > Bothriospondylus suffosus (Owen, 1875) Bothriospondylus > Bothriospondylus robustus (Owen, 1875) >> Marmarospondylus robustus (Owen, 1875) Bothriospondylus > Bothriospondylus madagascariensis (Lydekker, 1895) [?(Sauropod indet (Lapparent, 1943) = Bothriospondylus madagascariensis) LN=NN ]
Isolated vertebrae and limb elements of at least 10 individuals
Lavocat, R. 1955. Sur un membre antérieur du Dinosaurien sauropode Bothriospondylus Owen recueilli à Madagascar. Comptes rendus de l\\\'Academie des Science 240:1795-1796. [ On the forelimb of the sauropod dinosaur Bothriospondylus Owen recovered in Madagascar.Note of M. René Lavocat presented by M. Charles Jacobs. ]
Translated by Jeffrey A. Wilson University of Chicago Department of Organismal Biology & Anatomy October 1996
Observations on a specimen found recently in Madagascar. Characters of the hand: confirmation of the presence of a single ungual phalanx, situated on the thumb. Of the carpus: presence of small bones make clearer the homologies of the main bone.
On two important points the understanding of the forelimb of sauropod dinosaurs was until now incomplete and uncertain. The numerous reconstructions showing three ungual phalanges on each hand are purely hypothetical. C. W. Gilmore, after other authors, considered it very probable that there was only one ungual phalanx, that of the thumb, and that the others were absent or unossified. \\\"In view of the fact that a considerable number of articulated fore feet of the Sauropoda are now known and that none has been discovered with more than a single clawed ungual in association, the negative evidence thus accumulated seems to indicate there was only one.\\\"
The important portion of a skeleton which I have collected in Madagascar, as part of a mission which has received support from scientific institutions of France and Madagascar and of the Geological Survey of Madagascar, considerably reinforces the opinion of Gilmore. Indeed, the complete left forelimb has been found in anatomical connection with a single ungual phalanx preserved, that of the thumb.
Also, as in Gigantosaurus of East Africa, Apatosaurus of America and others, the second phalanx of digit II seems to be reduced to a strong nodule. Finally, the excavation which has allowed me to free the right limb of Bothriospondylus of Madagascar, of which the manus was very disassociated, has also supplied a single ungual phalanx, exactly symmetrical with that of the left hand. In view of the conditions of the site, observed in great detail, these facts--without perhaps definitive certainty--seem to support very strongly the opinion of Gilmore.
Another problem is that of the structure of the carpus. Very rarely are the discoveries pertaining to this region really in place. Usually researchers have attributed to the carpus one isolated element found nearby. Sometimes one, sometimes two bones of fairly large size are accepted, generally considered as the radiale and the ulnare. Such-and-such small bones found in proximity were also reported as carpals, with doubt and without precise determination.
H. F. Osborn has observed that the reputed radiale, having in fact precise articular facets with the metacarpals, should be in reality equivalent to distal ossicles. The newly excavated specimen supplies in favor of this opinion an argument which we think decisive. Indeed the main bone of the carpus, of form and shape comparable to those known, is clearly in anatomical connection with metacarpals I, II, and probably III.
Furthermore, resting on the proximal portion of this bone, two others of reduced size can be observed. The first, of approximately circular section like that of a torus, follows of very closely the contour of the main carpal, making a quarter of a circumference on its external border then dorsal. The other, not well seen and difficult to remove, seems to be of sub spherical form. It is situated on the palmar side external to the main carpal.
The exact homology
A radiale and a centrale? two centrales? from these elements it is difficult to decide. But it seems that, whatever this homology, the mere presence of these bones suffice to prove that in the case of Bothriospondylus, and quite probably other genera, that it is not with the radiale that one should liken the main bone, but with the elements of the distal series.
The remarkable preservation of these specimens, not deformed, in good anatomical connection and easy to remove, supported by the detailed observations of the field, allows then the specification of two important points of the anatomy of sauropods, points which the research done in rich localities of other regions have not permitted to elucidate. The new excavations, which we think follow closely on the fossil points already recounted, could be enterprises with much hope.
Source: Polyglot Paleontologist
Lydekker, 1895
Time
Jurassic Middle Bathonian
Classification
Saurischia Sauropodomorpha Sauropoda Brachiosauridae
Diet
Herbivore
Fossilsite
Isalo Formation, Majunga, Madagascar
Fall Under
Bothriospondylus
Info
Bothriospondylus (Owen, 1875) = ?Marmarospondylus (Owen, 1875) Bothriospondylus > Bothriospondylus suffosus (Owen, 1875) Bothriospondylus > Bothriospondylus robustus (Owen, 1875) >> Marmarospondylus robustus (Owen, 1875) Bothriospondylus > Bothriospondylus madagascariensis (Lydekker, 1895) [?(Sauropod indet (Lapparent, 1943) = Bothriospondylus madagascariensis) LN=NN ]
Isolated vertebrae and limb elements of at least 10 individuals
Lavocat, R. 1955. Sur un membre antérieur du Dinosaurien sauropode Bothriospondylus Owen recueilli à Madagascar. Comptes rendus de l\\\'Academie des Science 240:1795-1796. [ On the forelimb of the sauropod dinosaur Bothriospondylus Owen recovered in Madagascar.Note of M. René Lavocat presented by M. Charles Jacobs. ]
Translated by Jeffrey A. Wilson University of Chicago Department of Organismal Biology & Anatomy October 1996
Observations on a specimen found recently in Madagascar. Characters of the hand: confirmation of the presence of a single ungual phalanx, situated on the thumb. Of the carpus: presence of small bones make clearer the homologies of the main bone.
On two important points the understanding of the forelimb of sauropod dinosaurs was until now incomplete and uncertain. The numerous reconstructions showing three ungual phalanges on each hand are purely hypothetical. C. W. Gilmore, after other authors, considered it very probable that there was only one ungual phalanx, that of the thumb, and that the others were absent or unossified. \\\"In view of the fact that a considerable number of articulated fore feet of the Sauropoda are now known and that none has been discovered with more than a single clawed ungual in association, the negative evidence thus accumulated seems to indicate there was only one.\\\"
The important portion of a skeleton which I have collected in Madagascar, as part of a mission which has received support from scientific institutions of France and Madagascar and of the Geological Survey of Madagascar, considerably reinforces the opinion of Gilmore. Indeed, the complete left forelimb has been found in anatomical connection with a single ungual phalanx preserved, that of the thumb.
Also, as in Gigantosaurus of East Africa, Apatosaurus of America and others, the second phalanx of digit II seems to be reduced to a strong nodule. Finally, the excavation which has allowed me to free the right limb of Bothriospondylus of Madagascar, of which the manus was very disassociated, has also supplied a single ungual phalanx, exactly symmetrical with that of the left hand. In view of the conditions of the site, observed in great detail, these facts--without perhaps definitive certainty--seem to support very strongly the opinion of Gilmore.
Another problem is that of the structure of the carpus. Very rarely are the discoveries pertaining to this region really in place. Usually researchers have attributed to the carpus one isolated element found nearby. Sometimes one, sometimes two bones of fairly large size are accepted, generally considered as the radiale and the ulnare. Such-and-such small bones found in proximity were also reported as carpals, with doubt and without precise determination.
H. F. Osborn has observed that the reputed radiale, having in fact precise articular facets with the metacarpals, should be in reality equivalent to distal ossicles. The newly excavated specimen supplies in favor of this opinion an argument which we think decisive. Indeed the main bone of the carpus, of form and shape comparable to those known, is clearly in anatomical connection with metacarpals I, II, and probably III.
Furthermore, resting on the proximal portion of this bone, two others of reduced size can be observed. The first, of approximately circular section like that of a torus, follows of very closely the contour of the main carpal, making a quarter of a circumference on its external border then dorsal. The other, not well seen and difficult to remove, seems to be of sub spherical form. It is situated on the palmar side external to the main carpal.
The exact homology
A radiale and a centrale? two centrales? from these elements it is difficult to decide. But it seems that, whatever this homology, the mere presence of these bones suffice to prove that in the case of Bothriospondylus, and quite probably other genera, that it is not with the radiale that one should liken the main bone, but with the elements of the distal series.
The remarkable preservation of these specimens, not deformed, in good anatomical connection and easy to remove, supported by the detailed observations of the field, allows then the specification of two important points of the anatomy of sauropods, points which the research done in rich localities of other regions have not permitted to elucidate. The new excavations, which we think follow closely on the fossil points already recounted, could be enterprises with much hope.
Source: Polyglot Paleontologist